It is often desirable to temporarily close off drains to prevent various liquids from flowing therein. Particularly, when handling hazardous liquids in the vicinity of a drain, such as a storm drain or manhole, it is desirable to temporarily seal off the drain to prevent any hazardous liquid that may be accidentally spilled on the ground from entering the drain. Some known methods of sealing off a drain to prevent the possible ingress of liquids include providing custom fitted rigid covers, utilizing manual or automatic cutoff valves, covering the drain with a flexible material (e.g., canvas) and covering the flexible material with dirt or sand, and utilizing a sheet of polyurethane, vinyls, and other pliable materials to cover the drain. However, these known methods of drain isolation have certain practical limitations to their usefulness.
Utilizing custom fitted rigid covers or cutoff valves requires extensive preparation and installation efforts. Manufacturing a custom fitted cover and/or installing cutoff valves are both time consuming endeavors. Neither a custom fitted cover nor an installed cutoff valve can be easily adapted for use in covering and isolating drains other than the one for which the cover or valve was specifically designed, and they cannot be driven over. Moreover, once a custom fitted cover or cutoff valve is in place in a drain or drain system, neither is readily removable and/or transportable to another location for use.
Utilizing a flexible material held in place by dirt, sand or water to seal off a drain also presents certain problems in that such a covering is difficult to work with and is cumbersome and time consuming to implement in emergency situations. The effective seal surrounding the drain is limited by the dirt or sand utilized to hold the flexible material in place, and is further limited in that the dirt or sand may be washed away or eroded during flooding. In addition, water-filled drain blockers cannot be driven over. Such a drain covering has limited reusability and transportability, and the seal effectuated thereby has little resistance to the shear forces of onrushing liquids.
The present invention is directed toward overcoming one or more the above-mentioned problems.